The sensing equipment looks at density variation in the soil. Since explosives have a certain characteristic density they can be detected whether they are held in plastic or steel canisters.
And underground tunnels are probably too deep. Typically landmines are only in the first 12-18" of soil.
I think the advantage of aircraft is that the equipment is held suspended above the area and therefor personal risk of injury is minimized while the entire area is surveyed and then the equipment can move on to the next area. In ground survey work the equipment may be blocked due to the mine pattern and must remain in the area until the hazards are removed, then it can continue on it's way. In effect, the aerial survey equipment is more cost effective and profitable.
Inevitably, our technology will have many other uses including pipeline, archaeological and geological surveying, leading to other lucrative areas of commercial opportunity for Mineseeker Operations.
"My DD shows that our competition for land mine detection is Raytheon. There are others as well. But from what I can see out there, none of them are using aviation. All land vehicles and hand held sensors etc. "
I thought I saw another company listed at the conference, one with an UAV.